Display apparatus

Abstract

A display apparatus and a compensation circuit are provided. The display apparatus includes a display screen, a sound reproduction device and a power supply circuit. The power supply circuit includes a rectifier circuit and a compensation circuit. The rectifier circuit is used to convert an alternating current to a direct current. The compensation circuit is used to compensate for a parasitic signal of a synchronous rectification MOSFET in the rectifier circuit, thereby reducing heat generated by the MOSFET.

What is claimed is: 
     
       1. A display apparatus, comprising:
 a display screen configured for image display; 
 a sound reproduction device configured to play sound; 
 a power supply circuit configured to provide electric energy to a load of the display apparatus; and 
 a controller; 
 wherein the power supply circuit comprises:
 a rectifier circuit and a compensation circuit; wherein
 the rectifier circuit is configured to convert alternating current into direct current; and 
 the compensation circuit is configured to compensate a parasitic signal of a synchronous rectification Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) in the rectifier circuit; 
 wherein the rectifier circuit comprises a closed loop, wherein the closed loop includes a secondary coil, the synchronous rectification MOSFET and a load; and 
 the compensation circuit comprises: an electromagnetic induction coil placed in the closed loop of the rectifier circuit; wherein 
 the electromagnetic induction coil is configured to generate a compensation signal based on a closed loop current in the closed loop, wherein the compensation signal is used to compensate the parasitic signal of the synchronous rectification MOSFET in the rectifier circuit; 
 wherein the controller is configured to control the synchronous rectification MOSFET,
 a source of the synchronous rectification MOSFET is connected with the secondary coil and a first terminal of the electromagnetic induction coil, a drain of the synchronous rectification MOSFET is connected with the load in the closed loop and the controller respectively: and a second terminal of the electromagnetic induction coil is connected with the controller; 
 the electromagnetic induction coil is configured to generate the compensation signal between the first terminal and the second terminal based on the closed loop current in the closed loop; 
 the controller is configured to generate a control signal for controlling the synchronous rectification MOSFET according to a voltage between the second terminal of the electromagnetic induction coil and the drain of the synchronous rectification MOSFET. 
 
 
 
 
     
     
       2. The display apparatus according to  claim 1 , wherein:
 the controller comprises: a Synchronous Rectification (SR) drive chip with a CS pin, a GND pin and a DRV pin; 
 the CS pin of the SR drive chip is connected with the second terminal of the electromagnetic induction coil; 
 the GND pin of the SR drive chip is connected with the drain of the synchronous rectification MOSFET; 
 the DRV pin of the SR drive chip is connected with a gate of the synchronous rectification MOSFET. 
 
     
     
       3. The display apparatus according to  claim 2 , wherein the controller is further configured to:
 in response to the control signal sent from the SR drive chip to the gate of the synchronous rectification MOSFET being a low-level signal, cause a turning-off between the source and the drain of the synchronous rectification MOSFET; 
 in response to the control signal sent from the SR drive chip to the gate of the synchronous rectification MOSFET being a high-level signal, cause a turning-on between the source and the drain of the synchronous rectification MOSFET. 
 
     
     
       4. The display apparatus according to  claim 2 , wherein:
 the electromagnetic induction coil comprises at least one winding of wire. 
 
     
     
       5. The display apparatus according to  claim 4 , wherein:
 the rectifier circuit and the compensation circuit are disposed on a single-sided PCB; 
 the electromagnetic induction coil is a piece of wire connecting between a pin of the controller and a pin of the synchronous rectification MOSFET. 
 
     
     
       6. The display apparatus according to  claim 1 , wherein:
 the parasitic signal is generated by a parasitic inductance on a pin of the synchronous rectification MOSFET. 
 
     
     
       7. The display apparatus according to  claim 6 , wherein:
 the parasitic signal and the compensation signal are voltage signals.